What is the Present Perfect Tense?
The Present Perfect tense helps us talk about actions that started in the past and are still true now. It connects the past with the present.
We form the Present Perfect with have 或 has 以及 past participle of the main verb.
- I have lived here.
- She has worked a lot.
When Do We Use 'For'?
我们使用 for to say *how long* something has happened. It tells us the total amount of time, or the duration.
试想一下 for as answering the question 'How long?'.
- 我们使用 for with periods of time:
- for two hours
- for three days
- for five years
- for a long time
When Do We Use 'Since'?
我们使用 since to say *when* something started. It tells us the exact starting point in time.
试想一下 since as answering the question 'When did it start?'.
- 我们使用 since with specific points in time:
- since Monday
- since 2020
- since last week
- since I was a child
How Are 'For' and 'Since' Different?
The main difference is that for tells you the length of time, and since tells you the beginning of that time.
- For = duration (how long)
- Since = starting point (when it began)
Look at these examples to see the difference clearly:
- I have lived here for ten years. (Duration: 10 years)
- I have lived here since 2014. (Starting point: the year 2014)
| 对于 | Since |
|---|---|
| Duration | Starting Point |
| How long? | When did it start? |
| a week | Monday |
| two years | 2022 |
| three hours | 6 o'clock |
示例
- I have known him for a long time.
- She has worked at Langcom since January.
- They have been married for twenty years.
- We haven't seen them since last summer.
- He has played the guitar for five months.
- My brother has lived in London since he finished university.
练习
西班牙语母语者常犯的错误
A common mistake for Spanish speakers is to use the Present Simple or Past Simple instead of the Present Perfect with for 和 since.
- 错误： I live here for two years.
- 正确： I have lived here for two years.
另一个错误是混淆 for 和 since. Remember, for is for the length of time, and since is for the moment it started.
- 错误： I have studied English since three months. (使用 for with 'three months' because it's a duration.)
- 正确： I have studied English for three months.
- 正确： I have studied English since March. (使用 since with 'March' because it's a starting point.)
常见问题
Can I use 'for' and 'since' with other tenses?
No, for A1 English, you will primarily use for 和 since with the Present Perfect tense to talk about actions that started in the past and continue now.
What is the difference between 'for a long time' and 'since a long time'?
You should always say for a long time. A long time is a duration, so we use for. We do not say since a long time.
Is 'have been' the same as 'have lived'?
Not exactly. Have been is the Present Perfect of the verb to be. Have lived is the Present Perfect of the verb to live. Both can be used with for 和 since. 例如，, I have been here for an hour 或 I have lived here for an hour.
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